Sunday, April 10, 2016

SPECIFICATIONS for OPERATIONS of PROJECTS


Post 140   by Gautam Shah

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Projects or their near independent systems, when nearly ready, begin to function or need to be operated early. Systems, for example, such as the load-bearing entities become operative as soon as installed or the supports are removed. Similarly systems like stairs and elevators or water supply etc. are made operative for use by construction personnel. Some systems need to be run-tested for certification, safety and other guarantees and warrantees to be effective

Towering inferno, a movie of 1974 showed how important are the Operations Manual and Specifications for fighting fires
 A system that is operative also becomes due for regular maintenance, servicing, repair, safety and security observance, and comes under the scope risk-management (such as insurance, fire, etc.). Operations’ Specifications relate to terms and conditions of operating and maintaining various systems of the project. For small, simple and projects of routine nature there may not be any acute need to create a set of such documents. Complex projects, however, require professional operators who may need not be the original contractor or vendors. These third party operators need a formal assignment of their work and responsibilities. The assignments delineating these are the operations manuals. Operations manuals are not just handed to assigned or contracted operators, but placed in an accessible location for emergency reference.

Escalator maintenance Operation > Wikipedia image by Dailongumuneka
Projects of routine and simple nature are distinctly delivered - handed over to the client or user, according to a defined process and schedule. The client or user, thereafter on their own, or through other agencies, manage and operate the system.

In case of complex projects, however, consist of several subsystems which begin to be operative as soon as these are installed. Contractors and vendors use such subsystems during the execution of the project (such as stairs, drainage & water supply system etc.), and sometimes manage them till the project is delivered. In cases like, turnkey projects, some of the subsystems must be operated for trial and verification.

Nose section of Boeing 747 tested with pressure tanks > Wikipedia image by Oliver Cleynen
Operations specification for traditional material specifications+ processes of construction or assembly are different from projects “delivered” through Performance Specifications. Projects conceived through Performance Specifications invariably have many built in provisions for care of the main and subsystems during their emergent phase. For routine projects, in many organizations, the job of operations and maintenance is handled through departmental facilities or out sourced to specialized agencies. In both cases, yet a strategy is required for dealing with probable conditions and also for less-predictable situations (disasters, crisis). Designers of the system may provide such a strategy, or specialist agencies are required to prepare the operational specifications.

Mech+Elec+Plumbing MEP area > Wikipedia image by Eric T Gunther 
 
Forms of Operations Specifications

Operations specifications become key instructions during crisis. The agency that evolves the operational specifications, such as Owner, Designer, or Operator of the systems, each may adopt a varied strategy, often lacking coordination to deal with the situation. Professionals are now available, who can independently assess a building system, and prepare a set of operations specifications.
 
During emergency there is little time for understanding a layout > Wikipedia image by Cpl Trent A. Randolph

Operations specifications are often more graphical then written to make its access non technical, and free of language barriers. Many specifications are in the form of signage, instructions or warning signals. These specifications may not occur as a single comprehensive document but distributed across the estate. Repairs and maintenance work, need to be scheduled with other plans of actions. Operations specifications also include methods of observance, supervision and feedback systems.
 
Complex entities require equally meticulous schemes for operations > Wikipedia image by Reinraum
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Conditions for Creating and Providing the Operations Specifications

1          System Designer, System Provider (contractor, fabricator, vendor), and the System Operator, each of the roles should be clearly defined.

2          A System Provider must distinctly (formally) handover (deliver) the System (whole or self-sufficient parts of it) to the Client or appointed System Operators, as provided in the contract.

3     A System Designer and System Provider, together evolve the Operations Specifications. Only one of them is made responsible for Formal Transfer of the Operations Specifications' Documents to the operative agency.

4          System Designer (or the client) must see those necessary guarantees as available from Vendors and Sub contractors, and as provided by the main System Contractor, are transmitted to the Client. Alternatively a third party agency is appointed to create them afresh, and also affect such a transmission of guarantees.
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Wednesday, April 6, 2016

STEPS and STAIRS

Post 139   by Gautam Shah

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We need to move, along, away or towards the gravity. These modalities form transfer systems. The transfer systems along the gravity include paths, corridors, passages, etc. Transfer systems away or towards the gravity are perpendicular or inclined, and include firemen sliding poles, garbage chutes, emergency evacuation tubes, steps, stairs, ladders, slides, escalators, ramps and elevators. Some can be of both categories, like automated walkways, cable hung cars, roller coasters, conveyers, etc.
 
Climbing up the rock face at Angel's landing (Zion National Park) > Wikipedia image by Alex Proimos from Sydney Australia

All movements are essentially directional but transfer systems occur in unison, for two way movements. The other segment, however, manifests in some other situation, occasion, location or format. An escalator as an unidirectional system is more efficient than a mixed movement system like a stair. The gravity accelerates the down-movement, and inclination retards the rate of passage.

Jain Pilgrims on Shatrunjaya hill, Palitana Gujarat India > Flickr image by Arian Zwegers
 
Regularized transfer systems are uninterrupted services, and have width or passage way as the restrictor. Other restraining factors include speed of movement (goods or people, etc.), acceleration-de-acceleration, intermediate entry-exit openings, and safety. Carriage transports such as elevators are discontinuous services, and restrained by the frequency of service and capacity of the module.
 
Stairs and Escalators at Cabot Circus Shopping Centre, Bristol England > Wikipedia image by Arpingstone

Stairs and Escalators are stepped and inclined, transfer systems. Both provide uninterrupted transfer services. Use of stairs requires some orthopaedic proficiency and cautious posturing, but automated escalators allow freedom to see around during the passage. Stairs can take mixed traffic of accent and descent, but escalators require different sets. Reverse escalator services are often not provided as stairs are not very strenuous to climb down.
 
142 Mts long Potemkin stairs Odessa (1834-41) made famous by movie The battle of Potemkin 1925 > Wikipedia image by Dezidor

Film shot of The Battle of Potemkin on Odessa steps
Stairs and escalators are point to point passageways, as there is no midway interference, except at landings. Mountain side steps when comparatively wide show midway disturbance when people climb up diagonally to increase the negotiated distance and thereby reduce the steepness. Escalators are designed to be intermittent systems reaching floor to floor. Escalators transiting multiple floors are not perceived to be safe. Similarly multi floor escalators combined with landing level automated walkways are not favoured.
 
Streets of Cusco Peru > Road Ramp and matching step gradient > Wikipedia image by Rod Waddington from Kergunyah Australia

Steps and Stairs generally have a pitch higher than ramps. Stairs are safer than ramps provided the person is fully mobile and orthopaedically fit, but ascent or descent over stairs, more strenuous than the ramps. A ramp can have gradually variable pitch, but a stair has to have a one continuous grade of pitch.
 
Grand Staircase of RMS Olympic > Wikipedia image
 
The inclination of steps is defined by the relationship of tread versus the riser of the steps. This relationship varies for steps and stairs used for different purposes, ranging from steep ladders to flatter ramps like foot-ways. The dimensions of tread and riser are proportional and can be plotted on a hyperbola. Certain formulas also provide such proportions: 2T + R = 650 to 680 mm or R x T = 43000 to 45000. For steeper pitch the additional effort required to work against the gravity reduces the efficiency.
 
Steps with alternating treads over steel rock slope of Pinnacles National Park California USA > Wikipedia image by Wing-Chi Poon
Stairs have a pitch of not less than 17.30° (5:16), and of not more than of 48.30° (9:8). Below these limits it becomes a ramp or foot-ways, and above it a ladder. A ladder is not a comfortable utility. Step-ladders are lower in pitch, less than 75° and require flat treads. Risers may be open or closed, for toe accommodation and handrails may or may not be provided. In the ladders’ class of stairs, some are easier to climb than others. Ladders are used for fire escapes, boiler rooms, fly galleries, attics, decks, etc. Rung ladders are pitched more steeply, above 75°, and have extremely narrow treads or round rungs to accommodate the foot. In certain cases, the space to accommodate the knee between steps may be necessary. Rung ladders usually do not require additional handrails as the side members of the ladder can be used for holding grips. Rung ladders are often caged for safety, though such cages are more useful for ascent then for descent. It is safer to climb down facing the ladder. Swimming pools, water tanks, and sewers have rung ladders. Manhole steps are very narrow in widths, but the width is otherwise compensated by its staggered placement. The same holds true, for climbers for bunk beds, whether in railways, buses, barracks or homes.

Temple steps Thanjavur Tamil Nadu India Wikipedia image by Thamizhpparithi Maari


 Steps are components of stairs. Stairs when open (to sky -not covered on sides or top) are considered steps. Steps are freer architectural appendage or inset elements to negotiate small height differences. Steps traditionally have had abutting walls on either side. Steps could have same tread-riser relationship but steps are less steeper. A staircase is an enclosed or caged set of steps to several floors.

High pitch Bathing Ghat steps of ChetSingh Ghar Benaras India > Wikipedia image by Patrick Barry from San Francisco USA
Minimum width required for low intensity unidirectional traffic is 600 mm, however most standards specify 900 as minimum width for escape in a hazardous situation. A two-way lane stair should be at least 11200 mm. Sufficient width space for movement is required at torso level, otherwise at feet level a minimum width of 250 mm is required. Where same step is to be used for placing either one of the feet, both, the step and passage widths of minimum width of 500 mm are necessary. Stairs less than 500 mm width are generally emergency stairs rarely to be used, or service stairs to be used by experienced persons. For single lane traffic 750 mm width is an accepted standard. Most of the building bylaws allow minimum 900 mm widths for private buildings. For public buildings a stair width of 1200 mm to 1500 mm is recommended. For pedestrian over bridges and other public thoroughfares, a stair width of 2400 is recommended. On public thoroughfares where traffic is totally segregated or is only one directional, the minimum stair width could be 1800 mm.
 
Stepped Caen Hill Locks of the Waterway on Kennet and Avon Canal Devizes Wiltshire England > Wikipedia image
 Many stepping arrangements are used for emergency and special purposes. Simplest is a knotted rope or a rope ladder secured to a wall or column. In many countries older buildings were required to confirm to new bylaws, open iron stairways on the building's exterior were placed. Open iron stairs, though are rendered useless by smoke from windows, so must be placed against a blank wall. One of the best fire escape stairs is a fully enclosed stairway in the building itself or in an adjoining tower. Uncoated or unprotected steel is highly hazardous during a fire as it expands and deforms the stairway. Wood though combustible catches fire slowly, and allows more escape time compared to an unprotected steel stair.
Fire exit stairs in Soho NYC > Wikipedia image by Jorge Royan

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BODYING of FIBERS, YARNS AND FABRICS

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